Effect of in vivo cadmium exposure on the respiratory burst of Marine Fish (Limanda limanda L.) phagocytes

Following the in vivo exposure of dab (Limanda limanda L.) to cadmium chloride, kidney phagocytes were collected and their respiratory burst measured in vitro using chemiluminescence. Fish were exposed to mean measured concentrations of 1.3, 2.7 and 5.5 mg Cd litre⁻¹ (as total cadmium ion) for a total of nine weeks, followed by a three week depuration period in clean sea water. Compared with control fish, the respiratory burst of kidney phagocytes from dab sampled after six weeks was significantly reduced in the 2.7 and 5.5 mg Cd litre⁻¹ treatments (Steel's test, p < 0.05). Significant reductions were observed in the respiratory burst of phagocytes from all cadmium exposed fish compared with control fish after nine weeks (Steel's test, p < 0.05). After a further three week depuration period in clean sea water, the respiratory burst of phagocytes from fish previously exposed to 1.3 and 2.7 mg Cd litre⁻¹ were still significantly less than in the control group (Steel's test, p < 0.05). Muscle tissue cadmium concentrations were also analysed, although there was no clear relationship between the muscle total cadmium levels and kidney phagocyte chemiluminescence. The results are discussed with respect to the possible mechanism(s) of cadmium immunotoxicity in dab and recommendations made for future work.     

Nondetrital and total metal distribution in core sediments from the U-Tapao Canal, Songkhla, Thailand

The U-Tapao Canal is the main source of freshwater draining into the outer part of Songkhla Lake, which is the most important estuarine lagoon in Thailand. Songkhla Lake is located in southern Thailand between latitudes 7°08' and 7°50' N and longitudes 100°07' and 100°37' E. Acetic acid (HOAc)-soluble Cu, Fe, Mn, Pb, and Zn and the total concentration of these metals along with Al concentration, organic carbon, carbonate, sand, silt, and clay contents were determined in 4 sediment cores obtained at selected intervals from the mouth of the canal to 12 km upstream. Readily oxidizable organic matter in the cores varies from 1.52% to 7.30% and is generally found to decrease seaward. Total concentrations of Al (61.7–99.0 g kg⁻¹; 2.29–3.67 mol kg⁻¹), Cu (12.4–28.2 mg kg⁻¹; 195–444 μmol kg⁻¹), Fe (25.2–42.0 g kg⁻¹; 451–752 mmol kg⁻¹), Mn (0.22–0.49 g kg⁻¹; 4.0–8.9 mmol kg⁻¹), Pb (16.7–43.1 mg kg⁻¹; 80.6–208 μmol kg⁻¹), and Zn (48.6–122.7 mg kg⁻¹; 0.74–1.88 mmol kg⁻¹) vary to a certain extent vertically and seaward in the U-Tapao Canal core sediments. These concentrations are at or near natural levels and show no indication of anthropogenic contamination.Overall, the data show that total metal concentrations in the surface and near surface core sediments are enriched in varying degrees relative to Al in the order of Zn>Mn>Pb>Fe>Cu. Chemical partitioning shows that the enrichment in the surface and near surface sediments is related to the relatively high proportion of the total metal concentrations (Mn>Zn>Fe>Cu>Pb) that occur in the acetic acid-soluble (nondetrital) fraction, and they generally decrease with depth. Nondetrital Cu, Pb, and Zn likely derive from those metals held in ion exchange positions, certain carbonates, and from easily soluble amorphous compounds of Mn and perhaps those of Fe. Diagenetic processes involving Mn and to a lesser extent, Fe compounds, as well as the vertical changes in the oxidizing/reducing boundaries, appear to be the most important factors controlling the behavior of the metals in these cores. Organic matter and the aluminosilicate minerals, however, appear to be less important carriers of the metals studied.     

Heavy metals and accumulation rates of sediments in Osaka Bay,the Seto Inland Sea,Japan

The metal load into sediments and the change in the sedimentary environment of Osaka Bay in the Seto Inland Sea have been studied through geochemical analysis of core sediments, using both Pb-210 dating and a selective chemical leaching technique. Analytical results from a 6-m core of sediment show that copper and zinc pollution started in the late 1800's and the present enrichment ratios of copper and zinc, relative to background levels (20 mg kg^–1 for Cu and 94 mg kg^–1 for Zn), are 2.8 and 4.1, respectively. The present anthropogenic copper and zinc loads into Osaka Bay sediments, are 47 and 368 ton yr^–1, while natural copper and zinc loads are 40 and 186 ton yr^–1, respectively. Osaka Bay sediment at the present day is considered to be seriously polluted by zinc, now. The vertical profiles of copper and zinc in four successively separated fractions (10% acetic acid soluble fraction: F-HAC, 0.1M hydrochloric acid-soluble fraction: F-HCl, hydrogen peroxide-soluble fraction: F-H₂O₂ and hydrofluoric acid-soluble fraction: F-HF) from the core sediments indicate that enrichments of copper and zinc in the upper layer of the sediment are dependent on increases in the metal contents of the F-HAC, F-HCl and F-H₂O₂ fractions. Copper in F-HAC, and zinc in F-HAC and F-HCl, seem to be of anthropogenic origin.Results of sequential studies of the whole Seto Inland Sea can be summarized as follows: At the present time, the sedimentary loads of copper and zinc over the whole Seto Inland Sea area are 630 and 3,500 ton yr^–1, respectively, while the natural and anthropogenic loads are 320 and 310 ton yr^–1 for copper and 1,800 and 1,700 ton yr^–1 for zinc, respectively.     

Influence of water temperature and oxygenation on the aerobic metabolic scope of Atlantic cod (Gadus morhua)

Environmental influences (temperature and oxygenation) on cod metabolism and their impact on the ecology of this species were investigated. Limiting oxygen concentration curves (O₂ level ranging between 15 and 100% air saturation) were established at 2, 5 and 10°C. The standard metabolic rate (SMR), the maximum metabolic rate and the metabolic scope were then modelled as functions of temperature and/or oxygen saturation. The mean SMR at 2, 5 and 10°C were 19.8±4.9, 30.8±6.1 and 54.3±4.1 mg O₂ h⁻¹ kg⁻¹, respectively. Between 2 and 5°C, the active metabolic rate of cod almost doubled from 65 to 120 mg O₂ h⁻¹ kg⁻¹, to reach 177 mg O₂ h⁻¹ kg⁻¹ at 10°C. In terms of metabolic scope (MS), the temperature rise from 2 to 5°C resulted in a two-fold increase from 45 to 89 mg O₂ h⁻¹ kg⁻¹, with MS reaching 123 mg O₂ h⁻¹ kg⁻¹ at 10°C. Our proposed model describing the impact of temperature and oxygen level provides new insight into the energetic interactions which govern the relationship between Atlantic cod and its environment. We re-examined published experimental and field studies from the angle of the regulation of metabolic power. We suggest that, when faced with heterogeneous or unstable hydrological conditions, cod tend to behaviourally maximise their metabolic scope. Through this adaptive response, fish reduce energy budgeting conflicts and presumably increase the probability of routinely operating away from lethal boundaries.     

Relationship between metallothionein, copper and zinc in perch (Perca fluviatilis) environmentally exposed to heavy metals

Hepatic levels of Cu, Zn and metallothionein (MT) in perch, caught in a Cu/Zn gradient from a brassworks, reflected the water concentration of Cu (1·0–9·4 ppb) and Zn (0·56–59 ppb). Significant correlations were found between hepatic Cu and MT levels (r = 0·72), and between Zn and MT levels (r = 0·69). There was an increase of the amount of Cu and Zn in the cytosolic fraction of the liver with increased hepatic levels of the metals. When liver samples. from perch caught at the most contaminated location, were run on a gel filtration column (Sephadex G-75) 78% of the cytosolic Cu and 24% of the Zn in the cytosol eluted together with MT.     

Cadmium, copper, lead and zinc in three species of planktonic crustaceans from the east coast of Corsica

Results of trace metal analyses performed on two species of Euphausiacea, Meganyctiphanes norvegica and Stylocheiron longicorne, and one species of Decapoda, Sergestes arcticus, collected off the east coast of Corsica, are reported. Analyses were carried out by atomic absorption spectrophotometry and by differential pulse anodic stripping voltammetry.S. arcticus contained lower concentrations of phosphorus (which was also analysed as a biological indicator), cadmium (0.33 μg g⁻¹), copper (17.7 μg g⁻¹), lead (2.13 μg g⁻¹) and zinc (51 μg g⁻¹) than the two Euphausiacea (0.50 μg Cd g⁻¹, 25.4 μg Cu g⁻¹, 4.03 μg Pb g⁻¹ and 59 μg Zn g⁻¹). Moreover, manganese concentrations were low in all the samples.When the results presented here are compared with previous results on phytoplankton and mesozooplankton, there appears to be no trend of trace metal enrichment from phytoplankton to the Decapoda.     

Copper in the resurrection fjord, Alaska

Copper concentrations have been measured in more than 200 samples collected from an Alaskan fjord and continental shelf and slope regions in the northwestern Gulf of Alaska. Concentrations were lowest (2·1 nmol kg⁻¹) at depths of 400–1000 m in the continental slope waters of the Gulf of Alaska. Copper increased systematically with decreasing salinities shoreward to concentrations >30 nmol kg⁻¹ in fjord surface waters during summer months of high freshwater runoff. Copper concentrations increased with depth at an inner fjord station where deep basin waters have restricted circulation, and these data together with surface (<5 cm) pore water copper concentrations (mean=122 nmol kg⁻¹) about an order of magnitude higher than bottom water copper concentrations are indicative of a flux of copper across the sediment-seawater interface. This latter was estimated at 32±12 nmol cm⁻² annually, and represented less than 20% of the annual input to fjord surface water (228–411 nmol cm⁻²) added during summer months. Mass balances in bottom waters indicate a vigorous recycling of copper with a residence time estimated at 21±11 days. Most copper that is remobilized in surface sediments is returned to bottom waters and little (3%) is removed by subsequent diagenetic reaction in the buried sediments. However, an estimate of copper accumulating in anoxic fjord sediments was comparable with copper added to fjord surface waters suggesting that input-removal reactions rather than internal cycling controls copper geochemistry in this estuary.     

Solvent extraction of copper acetylacetonate in studies of copper(II) speciation in seawater

A liquid-liquid partition, ligand exchange procedure involving the formation of copper(II) complexes with acetylacetone is presented for the determination of stability constants and concentrations of copper chelators in seawater. Acetylacetone competes with natural ligands for copper, and the equilibrium concentration of the copper acetylacetonate complex is used in speciation calculations. The concentration of the complex is calculated by partitioning a fraction of it into an organic phase and determining the total Cu concentration in that phase by back extracting with acid, and analyzing by flameless atomic absorption spectroscopy. The concentration of Cu acetylacetonate in seawater in equilibrium with the organic phase is calculated from the partition coefficient. The simple, thermodynamically well characterized procedure offers several advantages over previous techniques. Studies using organic free seawater and model ligands show good agreement between experimental and calculated conditional stability constants. Studies from seawater in Biscayne Bay, Florida, indicate two ligand types are present; type 1, K₁ = 1.2 × 10¹², C_L1 = 5.1 × 10⁻⁹ M; type 2, K₂ = 2.8 × 10¹⁰, C_L2 = 1.1 × 10⁻⁷ M. Speciation is dominated by ligand type 1. Depth profiles of [Cu(II)]_free/[Cu(II)]_total measured with the procedure at ambient copper concentrations show an increase from < 5 × 10⁻⁵ at 50–60 m to > 1 × 10⁻³ at the surface at two stations off the Florida coast.     

Metallothionein and heavy metal levels in rainbow trout (Salmo gairdneri) during exposure to cadmium in the water

Rainbow trout were exposed to 200 ppb cadmium in the water during four months at 5°C. The liver, kidney and gills were analyzed for cadmium, copper, zinc and metallothionein. Cadmium accumulated in all three organs and reached the highest concentration in the kidney. The zinc and copper concentrations were not altered during the experiment. The metallothionein concentration was significantly higher in liver of exposed fish than in control fish after three months. The kidneys reached significantly elevated levels of metallothionein in the exposed group after four months. These results demonstrate that metallothionein is induced by cadmium after exposure to the metal via water.     

Use of an ion exchange technique to measure copper complexing capacity on the continental shelf of the southeastern United States and in the Sargasso Sea

An ion exchange technique has been used to determine the copper complexing capacity (CuCC) of strong organic complexing agents at 21 stations across the continental shelf of the southeastern United States and in the western Sargasso Sea. The concentration of dissolved organic carbon (DOC) and total particulate materal (TPM), two pools of potential complexing agents, was also measured at each station. The CuCC ranged from 0.014 to 1.681 μM Cu dm⁻³ on the inner shelf, from 0.043 to 0.095 μM Cu dm⁻³ in mid and outer shelf waters, and from < 0.010 to 0.036 μM Cu dm⁻³ at the Sargasso Sea stations. The correlation between CuCC and both DOC and TPM is highly significant (α < 0.01). Two synoptic surveys of the distribution of DOC and TPM across the shelf showed that DOC ranges from > 3 mg C dm⁻³ nearshore to <1 mg C dm⁻³ offshore and that TPM ranges from > 50 mg dm⁻³ nearshore to <1 mg dm⁻³ offshore. Both TPM and DOC are most variable on the inner shelf. These data are consistent with CuCC data which indicate that the CuCC of inner shelf waters was relatively high and very heterogeneous. In contrast, DOC, TPM and copper complexing capacity are low and nearly invariant at the Sargasso Sea stations. We present a model of the distribution of complexing agents in different marine environments and hypothesize that the mechanisms underlying differences between environments relate to differences in the source(s) and nature of complexing agents in each system.     

Uptake of selenium and other oxyanionic elements in marine ferromanganese concretions of different origins

The concentration of selenium in marine ferromanganese concretions varies between 0.02 and 1.2 mg kg⁻¹, with an average of 0.6 mg kg⁻¹. This is about two orders of magnitude lower than previously reported. In contrast to minor cationic elements, the concentrations of selenium are relatively uniform between ferromanganese concretions of different origins, except for hydrothermal crusts. It shows the same trends of element enrichment as other oxyanionic elements. The incorporation of selenium into ferromanganese concretions is attributed to adsorption of selenate on iron and manganese oxides.     

Sedimentation rates and heavy metal pollution of sediments in the Seto Inland Sea

In the Hiuchi-Nada area of the Seto Inland Sea, Japan, sedimentation rates were determined with the Pb-210 technique, and heavy metals in sediments were also analyzed. Sediments were collected in twelve short sediment cores and a long sediment core, using 1-m and 6-m gravity corers.The sedimentation rates vary from 0.14 to 0.31 g cm^–2yr^–1. The highest sedimentation rate was observed in the central part of the area, while lower sedimentation rates were observed in the eastern part.In Hiuchi-Nada, a remarkable increase in copper and zinc contents is noticeable as early as the 1800's. Over the past 240 years a copper smelter at the south-western side of this area has been causing serious pollution of the sediment. Now, anthropogenic copper and zinc loads into the sediment are 123 and 376 ton yr^–1 compared to natural copper and zinc loads of 82 and 401 ton yr^–1, respectively. The highest level of copper and zinc pollution was observed in the 1960's, when the relative enrichments above background values (copper; 19 and zinc; 93 mg kg^–1) were 5.5 and 2.8, respectively.     

Interaction of cadmium and copper with surface-active organic matter and complexing ligands released by marine phytoplankton

The organic matter released by the marine phytoplankton species Dunaliella tertiolecta and its physico-chemical interaction with cadmium and copper ions were studied by electrochemical methods (differential pulse anodic stripping voltammetry (DPASV) and a.c. polarography). The interactions with cadmium and copper were studied at the model interface (mercury electrodesolution) and in the bulk phase by measuring the complexing ability of the released organic material.The axenic cultures were grown on different growth media, without and with trace metals and chelators. Culture media were analyzed 10 days after inoculation, containing 5 × 10⁵−1.2 × 10⁶ cells cm⁻³ when untreated or after separation of cells by gentle centrifugation.It was found that the content and type of the released surface-active material and complexing ligands depend on the initial composition of the growth media. In all cases, strong interaction of excreted organic substances with copper in the bulk phase and with cadmium at the model interface were observed.A rather high value of the complexing capacity, 9.5 × 10⁻⁷ mol Cu²⁺ dm⁻³, was found in the culture grown on medium without trace metals and chelators (medium I) whereas the surface activity of this culture was not high (0.2 mg dm⁻³ equivalent to Triton-X-100). Higher contents of surface-active material (0.8 and 1.0 mg dm⁻³) were found in cultures grown in media with trace metals and without chelators (II and III), accompanied by a high content of complexing ligands (5.8 × 10⁻⁷ and 9.5 × 10⁻⁷ mol Cu²⁺ dm⁻³). However, if the complexing capacity is calculated per cell the values obtained for cultures grown in media II and III (0.79 × 10⁻¹⁵ and 0.98 × 10⁻¹⁵ mol Cu²⁺ dm⁻³) are lower than for cultures grown on medium I (1.8 × 10⁻¹⁵ mol Cu²⁻ dm⁻³). The exceptional adsorption effects and the copper complexing capacity for medium 1, and the presence of cells with degenerative symptoms can be ascribed to stressed growth conditions, and, particularly, to deficiency of metals. A qualitatively similar behaviour has been observed in natural samples of estuarine waters, indicating the existence of stressed conditions during the mixing of fresh and saline waters.     

Zinc uptake and regulation by the sublittoral prawn Pandalus montagui (Crustacea: Decapoda)

The sublittoral decapod crustacean Pandalus montagui Leach in artificial seawater at 10°C regulates the total body zinc concentration to a constant level in dissolved zinc concentrations up to ca. 22 μg Zn l⁻¹, beyond which there is net accumulation of body zinc. This threshold of zinc regulation breakdown is lower than that in the littoral decapods Palaemon elegans (ca. 93 μg Zn l⁻¹) and Palaemonetes varians (ca. 190 μg Zn l⁻¹) under the same physico-chemical conditions. Correspondingly, zinc uptake rates of the three species of decapods decrease in the order P. montagui > P. elegans > P. varians. It is concluded that regulation of total body zinc concentration is more efficient in decapods adapted to the fluctuating environments of littoral habitats, possibly as a result of changes in permeability of uptake surfaces in combination with improved zinc excretion systems. The moult cycle is important in determining the ability of an individual prawn to regulate zinc. Body zinc in Pandalus montagui consists of at least two pools of zinc exchanging at different rates which the environment. Zinc and copper are not evenly distributed in the tissues of P. montagui.     

Trace metal distributions across the continental shelf near Otago Peninsula, New Zealand

The distributions of the trace metals iron (Fe), copper (Cu) and cadmium (Cd) along with hydrological parameters (salinity, temperature and reactive phosphate) across the New Zealand continental shelf near Otago Peninsula have been studied. This is a region in which the Subtropical Convergence (STC), a major oceanic front separating subtropical and subantarctic waters, is uniquely located close to land, permitting an examination of the influence of terrestrial sources of Fe and Cu on oceanic waters containing excess micronutrients. Acid-soluble (110 nmol kg⁻¹) and dissolved (6.3 nmol kg⁻¹) Fe concentrations were highest over the central shelf, and decreased rapidly across the mixing zone of the STC to about 5 nmol kg⁻¹ for both forms. The distribution of acid-soluble and dissolved Cu were similar to their counterparts for Fe. Depth-concentration profiles for acid-soluble Fe and Cu suggest resuspension of shelf sediments is the main source. The ratio of oxine-labile to acid-soluble Fe varied from 0.03 to 0.26, with the highest values found in the near surface waters. Oxine-labile Fe and Cu also decreased in concentration in a seawards direction, and with depth, indicating the influence of near surface processes on the reactivity of these elements. Cd concentrations across the continental shelf were very low (<200 pmol kg⁻¹) and exhibited no clear spatial trend and no correlation with phosphate. Comparison of the Cd/P ratio across the shelf indicated that the waters in this region were strongly depleted in Cd relative to P. Phosphate concentrations were lowest in neritic water and increased in the seawards direction because of mixing with nutrient-rich Subantarctic Surface Water.     

Organic complexation and its control of the dissolved concentrations of copper and zinc in the Scheldt estuary

Cathodic stripping voltammetry (CSV) is used to determine total (after UV-irradiation) and labile dissolved metal concentrations as well as complexing ligand concentrations in samples from the river Scheldt estuary. It was found that even at high added concentrations of catechol (1 m for copper and 0·4 m for iron) and of APDC (1 m for zinc) only part of the dissolved metal was labile (5–58% for copper, 34–69% for zinc, 10–38% for iron); this discrepancy could be explained by the low solubility of iron which is largely present as colloidal material, and by competition for dissolved copper and zinc by organic complexing ligands. Ligand concentrations varied between 28 and 206 n for copper and between 22 and 220 n for zinc; part of the copper complexing ligands could be sub-divided into strong complexing sites with concentrations between 23 and 121 n and weaker sites with concentrations between 44 and 131 n . Values for conditional stability constants varied between (logK′ values) 13·0 and 14·8 for strong and between 11·5 and 12·1 for weaker copper complexing ligands, whereas for zinc the values were between 8·6 and 10·6. The average products of ligand concentrations and conditional stability constants (a-coefficients) were 6 × 10² for zinc and 6 × 10⁶ for copper.The dissolved zinc concentration was found to co-vary with the zinc complexing ligand concentration throughout the estuary. It is argued that the zinc concentration is regulated, in this estuary at least, by interactions with dissolved organic complexing ligands. A similar relationship was apparent between the dissolved copper and the strong copper complexing ligand concentration. The total copper complexing ligand concentrations were much greater than the dissolved copper concentrations, suggesting that only strongly complexed copper is kept in solution.These results provide evidence for the first time that interactions of copper and zinc with dissolved organic complexing ligands determine the geochemical pathway of these metals.     

Profiles of dissolved and acid-leachable selenium in a sediment core from the lower St. Lawrence estuary

Concentrations of Se in the pore-water and in the solid phase, and the concentrations of other diagenetic constituents (Fe, Mn, phosphate, ammonium and I) in pore-water, were determined in a sediment core from a 350-m deep station in the lower St. Lawrence Estuary. The concentration of dissolved Se in pore-water was 2.1 nmol kg⁻¹ at the surface of the core, increasing to a maximum of 7.6 nmol kg⁻¹ at a depth of 12 cm, and thereafter decreasing gradually with depth. This profile is similar to the profiles of Fe and phosphate, whose concentration maxima occur around 10 cm. The concentration of total sedimentary Se remained almost constant with depth (≈ 0.75 mg kg⁻¹); however, a significant enrichment of oxalate-leachable Se was observed in the top 2 cm. The sedimentary cycling of Se appears to be closely related to that of Fe: adsorption of Se onto Fe oxyhydroxide at or near the sediment-water interface, release of the adsorbed Se by the reduction of Fe oxyhydroxide, and removal by formation of ferroselite (FeSe₂) at depth. The pore-water flux of Se was estimated by two different methods, firstly from the pore-water gradient, and secondly by applying a box model to the oxalate-leachable solid-phase Se data. The methods agree well both giving values for the flux of 0.11 nmol cm⁻² year⁻¹. This agreement suggests that the loss of labile Se in the sediment is balanced by the upward flux of dissolved Se.     

Alterations in hepatic metallothionein content in perch, Perca fluviatilis, environmentally exposed to cadmium

During recent years laboratory studies have demonstrated the presence of metallothionein in several species of teleosts.^1–3 The role of metallothionein (MT) in protection against cadmium toxicity has been investigated by exposing fish to high levels of cadmium in the water.^4–6 So far, however, few field studies have focused on the existence of MT and its role in subcellular distribution of cadmium.⁷ In the present study the synthesis of MT as a possible mechanism by which perch adapt to cadmium contamination was investigated in a wild population of perch. An increased MT content of perch liver was found to correlate to an increase in cadmium present in the liver.     

Cadmium,lead, copper,and zinc in Elminius modestus Darwin (Crustacea,Cirripedia) from Waitemata and Manukau Harbours,Auckland, New Zealand

Abstract

Concentrations of cadmium (Cd), lead (Pb), copper (Cu), and zinc (Zn) were measured in adult barnacles (Elminius modestus Darwin) from Waitemata and Manukau Harbours in the Auckland area, New Zealand. As in studies on sediments reported in the literature, it was possible to identify areas of likely anthropogenic influence, e.g., around the Auckland Harbour Bridge for Pb, Cu, and Zn. Groups of individuals with highest concentrations for these metals showed 19.8–23.8 mg Pb kg^?1, 198–266 mg Cu kg^?1, and 4460–6530 mg Zn kg^?1 (95% confidence limits, dry weight basis). Cd concentrations found for all barnacles from the Auckland area ranged from 0.8 to 3.1 mg kg^?1. Two samples from Omaha Beach, 60 km north of Auckland, were used as a reference. Accordingly, groups of individuals with lowest concentrations for Pb, Cu, and Zn could be allocated to this site using the Student‐Newman‐Keuls Multiple Range Test (0.5–1.3 mg Pb kg^?1, 8–10 mg Cu kg^?1, and 144–214 mg Zn kg^?1 ; 95% confidence limits). Only Cd concentrations were highest at Omaha Beach (8.6–12.1 mg Cd kg^?1 ). This result may have arisen from “naturally” increased bio‐availabilities of certain metals in mangrove systems which are reported in the literature. Generally, metal concentrations in barnacles from the Auckland Harbour area and from Omaha Beach were within the wider range for E. modestus as well as other barnacle species reported in the international literature.